That film was adapted from a 2011 case when two Chinese merchant ships were attacked and destroyed by a drug gang in the Golden Triangle, which prompted a cross-border hunt for the murderers.

Speaking about The Thunder and Operation Mekong, Chen Yuxin, who is the screenwriter for both, says: "The difficulty is how to blend the real case and fictional parts together.

"People want the details, but we also need to look at the bigger picture."

As for how the series can help focus more attention on the problem, Shen Yue, an officer from the Ministry of Public Security, who is in charge of cross-border cooperation fighting drug-related crimes, says: "We are urged to take a stronger international responsibility when it comes to fighting crime and cutting off its origins."

And the Thunder operation is just one part of the comprehensive action taken to tackle the problem.

Contact the writer at [email protected]